When to Plant Broccoli in Toole County, MT
Broccoli is a nutrient-dense cool-season crop that produces large central heads followed by smaller side shoots. It is one of the most popular garden vegetables.
Toole County, Montana is in USDA Zone 4a. The average last spring frost is May 24 and the first fall frost is September 17, giving you a growing season of approximately 116 days.
At an elevation of 7,194 feet, Toole County receives approximately 23.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Broccoli to ensure they mature before fall.
Toole County Soil Profile
Soil Type
Loam
Soil pH
6.8-8.2
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Broccoli Planting Timeline — Toole County, MT
Broccoli Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 12 | Apr 12 – Apr 26 |
| Transplant Outdoors | May 24 | May 24 – Jun 7 |
| Direct Sow | May 17 | May 17 – Jun 7 |
| Fall Sowing | June 25 | Jun 25 – Jul 9 |
| Harvest | July 26 | Jul 26 – Sep 6 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow Fall Sowing |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
60–90 days
Soil pH
6 – 7
USDA Zone
Zone 4a
Growing Season
116 days
Growing Tips for Toole County
Start seeds indoors 6-8 weeks before last frost. Provide consistent moisture to prevent hollow stems. Harvest heads before yellow flowers appear.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Isolate 1/2 mile from other brassicas. Biennial — must overwinter roots.
Broccoli in Other Locations
Frequently Asked Questions
When should I plant Broccoli in Toole County, MT?
Toole County is in Zone 4a with an average last frost of May 24. Plan your Broccoli planting based on this frost date — see the calendar above for exact timing.
What planting zone is Toole County, MT?
Toole County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 24 and first fall frost is September 17.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Toole County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.
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